A new technique for ureteral reconstruction using lingual mucosa grafts in a beagle model.

PURPOSE: To investigate the feasibility of ureteral reconstruction using lingual mucosa graft (LMG) and evaluate the histological changes of the engrafted LMG in beagles. METHODS: Twelve male beagle dogs were randomly divided into groups A, B and C (n = 4). A ventral ureteral defect was created by excising half of the ureteral wall. The length of the defect was 3 cm, 6 cm, and 10 cm in groups A, B, and C, respectively. The LMGs were harvested and employed to repair the ureteral defects in onlay fashion. Two dogs per group were sacrificed after 6 months, with additional two dogs per group sacrificed after 12 months. Intravenous urography (IVU) and macroscopic examination were performed to evaluate renal function and ureteral patency. Histological changes in the engrafted LMGs during the tissue incorporation process were assessed by histological analysis. RESULTS: There were no postoperative complications. Only one dog in group C developed a mild stricture near the proximal anastomosis. In the remaining 11 animals, IVU showed normal renal function and a wide ureteral caliber without stricture or fistula. The diameter of the LMG-reconstructed ureter was greater than that of the proximal and distal ureter (each p value < 0.01). The LMGs survived in situ with newly formed capillaries. The epithelium of the lingual mucosa resembled the urothelium in postoperative 12 months. CONCLUSION: This new technique for ureteral reconstruction using LMGs is feasible. This approach is a promising alternative clinical treatment for curing long ureteral strictures.

Experimental study on the repair of ureteral functional regeneration with highly bioactive extracellular matrix stent.

BACKGROUND: The research of extracellular matrix stent (ECM) has made some progress in the repair of urethra and bladder defects. OBJECTIVES: To observe the effects of highly bioactive ECM scaffold on the regeneration and repair of defects in long-segment ureteral replacement. MATERIAL AND METHODS: An animal model of long-segment ureteral defect was established and four-layer tubular highly bioactive ECM materials were prepared. After the ureteral defect was repaired through surgery, the rabbits in the negative control group were administered a non-bioactive stent, and rabbits in the observation group were treated with an ECM stent. RESULTS: Comparison of macro-indicators: The negative control group had a higher infection rate, a lower survival rate and more complications than the observation group (p < 0.05). The frequency of ureteral peristalsis in the negative control group was lower than in the observation group. In addition, the rate of urinary dysfunction was higher, and the ratio of ureteral diameter was lower in the negative control group than in the observation group (all p < 0.05). Comparison of histopathology: Three months after the operation, the vascular, smooth muscle and mucous membrane of the ureter in the observation group regenerated to close to normal ureteral tissue. There was no significant difference between the ureter regeneration in the repair area and the normal ureter tissue in the observation group 3 months after the operation. The number of regenerated muscle fibers in the observation group was significantly higher than that of the negative control group. Compared with the negative control group, the fibrous capsule was thicker, the percentages of CD31, CD3, CD68, CD80+, and CD163+ were higher, the scope of new smooth muscle fiber was expanded, fusion with the host muscle fibers was higher, and the neuromuscular junction (NMJ) structure was stronger in the observation group (all p < 0.05). CONCLUSIONS: A highly bioactive ECM stent can better regenerate the local anatomical structure and physiological function.

Clinical reappraisal and state of the art of nephropexy.

The diffusion of minimally invasive techniques for renal surgery has prompted a renewed interest in nephropexy which is indicated to prevent nephroptosis in symptomatic patients and to mobilize the upper ureter downward in order to bridge a ureteral defect. Recent publications have been reviewed to present the state of the art of the diagnosis and management of these two challenging conditions and to try to foresee the next steps. The evaluation of patients with mobile kidney can be made relying on diagnostic criteria such as ultrasound with color Doppler and measurement of resistive index, conventional upright X-ray frames after a supine uro-computerized tomography scan and both static and dynamic nuclear medicine scans, always with evaluation in the sitting or erect position. Laparoscopic nephropexy emerges as the current treatment option combining both objectively controlled repositioning of the kidney and resolution of symptoms with minimal invasiveness, low morbidity, and short hospital stay. The use of robotics is presently limited by its higher cost, but may increase in the future. Downward renal mobilization and nephropexy is a safe and versatile technique which has been adopted as a unique strategy or more often in combination with other surgical maneuvers in order to cope with complex ureteral reconstruction.

Clinical research of ureteral replacement using the Yang-Monti principle / 中华泌尿外科杂志

Objective We summarized the clinical experience of modified ileal ureter substitution for treating long segment ureteral defection.Methods We retrospectively analyze the clinical data of 2 patients with long segment ureteral defect who treated with Yang-Monti ileal ureter substitution between March 2015 and November 2015.One 75 years old male patient was diagnosed as upper ureteral malignance and solitary kidney.The length of defection from renal pelvis to bladder was 22 em.His serum creatinine was 100 μmol/L,blood urea nitrogen was 5.7 mmol/L,serum chloride was 98 mmol/L.Another one 41 years old female patient was diagnosed as middle and lower ureteral iatrogenic injury.The traumatic length was 15 cm.Her serum creatinine was 70 μmol/L,blood urea nitrogen was 5.1 mmol/L,serum chloride was 100 mmol/L.they were both treated by Yang-Monti ileal ureter substitution.The ileal intestinal segment was used for the ureteral replacement,which were more than 15 cm to the ilealcecum.The length of intestine was 10.0 cm and 7.5 cm,respectively.The ileal mesentery was preserved.After closing the mesangial hiatus,the ileal segment was pull into the retroperitoneal space and pulling out via descending colonic mesangial window.The ileal segment was divided into three parts,which was 2.5 to 3.0 cm in each part.Each part was opened via long axis and then rotated 90 degree.The 4-0 absorable suture was used to suture the edge of each intestinal part continuously.The sutured intestine was re-tubularized,using 4-0 absorable suture and the F16 catheter was used as the tube model.The length of reconstructed ureter was 22 cm and 18 cm,respectively.The neo-ureter was re-anastomosed with renal pelvis and bladder wall.Two F6 double J stents were placed in the neo-ureter.Results The operative time was 160 min and blood loss was 200 ml in the first case.In the second case,the operative time was 180 min and blood loss was 220 ml.No significant complications were noticed intra-operation and post-operation.Six months after operation,the male patient's serum creatinine was 112 pmol/L,blood urea nitrogen was 6.1 mmol/L,serum chloride was 106.0 mmol/L and electrolytes were normal.In another patient,serum creatinine was 79 μmol/L,blood urea nitrogen was 5.9 mmol/L and serum chloride was 103.0 mmol/L.The GFR was 24.9 ml/min and 22.1 m]/min 3 and 6 months after operation,respectively.Ureteral obstruction wasn't detected on IVU images 3 months after operation.Conclusions For patient with long ureteral defect,which cannot be replaced by other urinary tissue,YangMonti ileal ureter substitution is one of the optional modalities.As a new technique of ureteral substitution,Yang-Monti ileal ureter substitution is simple and fewer complications and can improve the quality of life in patient compared with traditional ureteral substitution.

Antireflux Surgery Using an Appendiceal Pedicle Graft in Vesicoureteral Reflux after Augmentation Gastrocystoplasty: A Case Report / 대한비뇨기과학회지

Under the specific circumstances the appendix may be an appropriate organ for plastic repair of a large ureteral defect. We report a case of antireflux surgery using an appendiceal pedicle graft in recurrent right vesicoureteral reflux after augmentation gastrocystoplasty and uretera1 reimplantation. This graft was successfully replaced the right lower ureter to repair long defect caused by postoperative adhesion and follow up urogram showed disappearance of reflux and improvement of hydronephrosis at three months postoperatively.